1. Field of the Invention
The present invention relates generally to valves and valve arrangements for interacting with various components of a material transfer or handling system, such as a pipeline in a loading or unloading application and, in particular, to a threaded valve arrangement that allows for quick closure and improved sealing properties, including more powerful “seating” of the actuation portion of the valve while requiring less space than comparable valves.
2. Description of Related Art
Valves are used in a variety of applications and systems that require the prevention, redirection or manipulation of various product and material streams, whether solid, semi-solid or fluid materials. As is known in the art, these materials flow through the material handling system, such as in pipelines and the like, in order to transfer the materials from location to location. In order to manage the direction, flow and other characteristics of the material transfer process, valve arrangements are utilized. For example, such valve arrangements may include gate valves, manifold valves, butterfly valves, flapper valves, etc.
With respect to these valve arrangements, it is desirous to provide for the quick opening and closure of such a valve for a variety of reasons, including safety reasons. For example, in the instance of a pipeline failure in an upstream portion of the pipeline, a downstream valve such as, for example, a gate valve must be quickly closed to prevent any further fluid communication of the product from the downstream location to the upstream location. This is particularly important where the pipeline failure contains hazardous materials that could adversely affect the surrounding community and/or surrounding habitat.
In addition, not only is the speed of closure important, but the valve must be “seated” or sealed sufficiently using the actuation portion (e.g., the gate) to prevent all communication between the upstream and the downstream portions of the pipe. Therefore, not only must the person quickly close the valve in certain situations, but the valve must provide the optimum sealing characteristics in order to ensure that no material moves through the actuation portion when it is in the “closed” position.
Another safety consideration with respect to valve arrangements is the position of the handle and stem with respect to the walkway or passageway adjacent the handle. For example, and according to the prior art, most valve stems and handles project from the valve and pipe and extend into the walkway, which may pose a safety risk. In addition, many such piping systems include very narrow passageways, such that the projection or extension of the valve stem and handle into these passageways must be minimized as much as possible.